유니몰프 PZT 액츄에이터를 이용한 평면 마이크로 이송장치 개발

남기호(Ki-Ho Nam),권현규(Hyun-Kyu Kweon),최성대(Sung-Dae Choi) 한국기계가공학회 2005 한국기계가공학회 춘추계학술대회 논문집 Vol.2005 No.-

개환 복분해 중합을 통한 가교형 폴리이미드 박막의 잔류응력 거동 및 특성 분석

남기호(Ki Ho Nam),서종철(Jong Chul Seo),장원봉(Won Bong Jang),한학수(Hak Soo Han) 한국고분자학회 2014 폴리머 Vol.38 No.6

본 연구에서는 미세 전자 소자용 절연박막 및 차세대 플렉시블 디스플레이 기판으로서 사용이 기대되는 폴리이미드(PI)에 개환 복분해 중합(ring-opening metathesis polymerization)이 가능한 환형 말단 캡핑제(end-cappingagent)인 cis-1,2,3,6-tetrahydrophthalic anhydride(CDBA)로 사슬 말단에 가교 반응이 된 가교형 폴리이미드를 합성하였다. 말단 캡핑제의 조성비에 따른 가교형 폴리이미드 박막의 잔류응력 거동은 thin film stress analyzer(TFSA)를이용한 wafer bending mothod로 온도에 따라 연속적인 거동을 in-situ로 측정하였다. 열특성은 시차 주사 열량계(DSC), 열기계 분석기(TMA) 및 열 중량 분석기(TGA)를 이용하여 측정하였고, 광학 특성은 자외선/가시광선 분광광도계(UV-vis)와 색차계(spectrophotometer)를 이용하였으며, 네트워크 구조의 모폴로지(morphology) 변화를 통해해석하였다. 말단 캡핑제의 조성비가 증가함에 따라 잔류응력은 27.9에서 -1.3 MPa로 초저응력 및 향상된 열 특성을 나타내었으나, 광학 특성은 감소됨을 보였다. 가교형 폴리이미드 박막의 우수한 특성 발현은 고집적도 다층 구조의 안정성 및 신뢰도가 요구되는 분야의 응용성이 확대될 것으로 기대된다. Cross-linked polyimides (PIs) were synthesized by reacting 4,4``-(hexafluoroisopropylidene)-diphthalic anhydride(6FDA) and 2,2``-bis(trifluoromethyl)benzidine (TFDB) with various ratios of the cross-linkable, end-capping agentcis-1,2,3,6-tetrahydrophthalic anhydride (CDBA) via ring-opening metathesis polymerization. Residual stress behaviorswere investigated in-situ during thermal imidization of the cross-linked PI precursors using a thin film stress analyzer(TFSA) by wafer bending method. The thermal properties were investigated via differential scanning calorimetry (DSC),thermomechanical analysis (TMA), and thermogravimetric analysis (TGA). The optical properties were measured byultraviolet-visible spectrophotometer (UV-vis) and spectrophotometry. All properties were interpreted with respect to theirmorphology of cross-linked networks. With increasing the amounts of the end-capping agent, the residual stress decreasedfrom 27.9 to -1.3 MPa, exhibited ultra-low stress and high thermal properties. The minimized residual stress andenhanced thermal properties of the cross-linked PI makes them potential candidates for versatile high-density multi-layerstructure applications.

광학 위상지연 조절을 위한 폴리이미드 공중합체 박막 제조

남기호(Ki-Ho Nam),이완수(Wansoo Lee),장원봉(Wonbong Jang),한학수(Haksoo Han) 한국고분자학회 2016 폴리머 Vol.40 No.4

서로 다른 주사슬 구조의 이무수물 3,3",4,4"-benzophenonetetracarboxylic dianhydride(BTDA)와 4,4"-(hexafluoroisopropylidene)- diphthalic anhydride(6FDA)에 4,4"-diaminodiphenyl ether(ODA)와 2,2"-bis(3-amino-4-hydroxyphenyl) hexafluoropropane diamine(AHHFP)를 다양한 몰 비로 각각 반응시켜 삼성분계 폴리아믹산 전구체를 합성하였고, 이를 단계적인 열적 이미드화 공정을 통하여 공중합 폴리이미드 박막을 제조하였다. 디아민 조성비에 따른 공중합 폴리이미드 박막의 광학 위상지연은 LCD 패널 측정장치를 이용하여 면 방향 위상지연(R0)과 두께 방향 위상지연(Rth) 값을 측정하였다. 광학 투과도와 황색도는 자외선/가시광선 분광광도계(UV-vis)와 색차계(color-difference meter)를 이용하여 측정하였고, 열 특성은 시차 주사 열량계(DSC)와 열 중량 분석기(TGA)를 이용하였으며, 조성비에 따른 모폴로지 변화를 통해 해석하였다. 제조된 박막의 특성변화는 그 화학구조 및 조성에 따른 모폴로지 변화와 매우 밀접한 관련이 있으며, 이에 따라 박막의 광학 위상지연 조절이 가능함을 확인하였다. Poly(amic acid)s were successfully synthesized from 3,3",4,4"-benzophenonetetracarboxylic dianhydride (BTDA) or 4,4"-hexafluoroisopropylidene diphthalic dianhydride (6FDA) with different molar fractions of 4,4"-oxyaniline (ODA) and 2,2"-bis(3-amino-4-hydroxyphenyl)hexafluoropropane diamine (AHHFP). Stepwise thermal imidization method were used for preparing polyimide copolymer films. Two-axis out-of-plane retardations were detected for optical retardation (R0 and Rth) measurement using an LCD panel measuring device. The optical transparency and yellow index were measured by a ultraviolet-visible (UV-vis) spectrophotometer and a color-difference meter. Their thermal properties were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The physical properties of PI copolymer films were found to be strongly dependent upon the morphological structure and composition. After all, Rth of PI copolymer films were possibly controlled.

α-Galactosidase를 생산하는 고온성 Bacillus coagulans KM-1 균주의 생화학적 특성

남기호 ( Ki Ho Nam ),장미순 ( Mi Soon Jang ),박희연 ( Hee Yeon Park ),이레나코네바 ( Elena Koneva ) 한국수산과학회 2014 한국수산과학회지 Vol.47 No.5

A bacterium producing α-galactosidase (α-d-galactoside galactohydrolase, EC 3.2.1.22) was isolated. The isolate, KM-1 was identified as Bacillus coagulans based on its 16S rRNA sequence, morphology, and biochemical proper-ties. α-Galactosidase activity was detected the culture supernatant of B. coagulans KM-1. The bacterium showed the maximum activity for hydrolyzing para-nitrophenyl-α-d-galactopyranoside (pNP-αGal) at pH 6.0 and 50℃. It hydro-lyzed oligomeric substrates such as melibiose, raffinose, and stachyose liberating a galactose residue, indicating that the B. coagulans KM-1 α-galactosidase hydrolyzed α-1,6 linkage. The results suggest that the decreased stachyose and raffinose contents in fermented soybean meal are due to the α-galactosidase activity.

무색 투명 폴리이미드 박막의 잔류응력 거동 및 특성분석

남기호(Ki Ho Nam),이완수(Wan Soo Lee),서광원(Kwang Won Seo),한학수(Hak Soo Han) 한국고분자학회 2014 폴리머 Vol.38 No.4

이무수물인 4.4`-(hexafluoroisopropylidene)-diphthalic anhydride(6FDA)에 bis(3-aminophenyl) sulfone(APS), bis[4(3-aminophenoxy)-pheny1] sulfone (BAPS), 2,2-bis(4-aminophenyl)-hexafluoropropane(6FPD), 2,2-bis[4-(4-aminophenoxy)-phenyl]hexafluoropropane(6FBAPP). 2,2`-bis(trifluoromethyl)benzidine(TFDB) 및 1.4-phenylene-diamine(PDA) 등 6종류의 디아민 단량체를 이용하여 폴리이미드(PI) 박막을 제조하였다. 이들 박막의 잔류응력 거동은 thin film stress analyzer(TFSA)를 이용하여 전구체의 열적 이미드화에 따라 in-situ로 측정하였음, 모포로지변화를 통해 해석하였다. 박막의 분자 배향성 및 질서도에 따라 잔류응력은 23.1에서 12.5Mpa의 값을 보였으며, 사슬이 강직할수록 감소하였다. 열 특성은 시차 주사 열량계(DSC). 열 중량 분석기(TGA) 및 열 기계 분석기(TMA)를 이용하여 측정하였고, 광학 특성은 자외선/가시광선 분광광도계(UV-vis)와 색차계를 이용하였다. 제조된 박막의 특성변화는 그 화학구조와 밀접한 관련이 있으며, 잔류응력과 광학 특성은 트레이드-오프(trade-off)됨을 확인할 수 있었다. A series of polyimide (PI) was prepared by reacting 4`4-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA) as the anhydride and bis(3-aminophenyl) sulfone (APS), bis[4-(3-aminophenoxy)-phenyl] sulfone (BAPS), 2,2-bis(4-aminophenyl)-hexafluoropropane(6FPD), 2,2-bis[4-(4-aminophenoxy) -phenyl]hexafluoropropane (6FBAPP), 2,2`-bis(trifluoromethyl)benzidine(TFDB), or 1,4-phenylendiamine (PDA) as the diamine. Residual stress behaviors were detected in-situ during thermal imidization of the oplyimide precursors using a thin film stress analyzed (TFSA), and inter-preted with respect to their morpholgy. According to the molecular orientation and packing order, the residual stress ver-ied from 23.1 to 12.5 Mpa. Decreased with increasing chain rigidity. The thermal properities of the PI films were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis(TGA), and thermomechanical analysis (TMA). Their optical properties were measured by ultraviolet-visible spectrophotometer (UV-vis), and spec-trophotometry. The properties of PI films were found to be strongly dependent upon the morphological structure. How- ever, trade-offs between residual stress and optical properties were identified.

Laser-Induced Graphene on Polymers: From Formation Mechanism to Green Applications

Ki-Ho Nam(남기호) 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.2

녹차 및 연잎 열수추출물 처리가 염장고등어의 저장 중 품질특성에 미치는 영향

남기호 ( Ki Ho Nam ),장미순 ( Mi Soon Jang ),이두석 ( Doo Seog Lee ),윤호동 ( Ho Dong Yoon ),박희연 ( Hee Yeon Park ) 한국식품저장유통학회(구 한국농산물저장유통학회) 2011 한국식품저장유통학회지 Vol.18 No.5

This study was carried out to analyze the quality change of mackerel treated of green tea and lotus leaf boiled water extracts. And investigate the antioxidant effects of them on the lipid peroxidation of mackerel during storage at 4℃ for 28 days. It was estimated periodical measurements of proximate composition, pH, carbonyl, volatile basic nitrogen, trimethylamine-N, acid, peroxide and thiobarbituric acid values. It had no effect on proximate composition compared with non- treated control nearly but, pH of all the samples was increase during 28 days continuously. The contents of volatile basic nitrogen and trimethylamine-N lower than control during storage. Also, acid, peroxide and thiobarbituric acid values of mackerel treated of green tea and lotus leaf boiled water extracts were significantly lower than control throughout storage period. Especially, mackerel treated of 2% green tea and lotus leaf boiled water extracts shows that more effective than 1% of things in antioxidant during storage. Results indicate that the application of green tea and lotus leaf boiled water extract on the surface of mackerel may be useful to lower the rancidity degree and fish odor during storage.

해수순치산 및 담수양식산 철갑상어(Acipenser oxyrinchus)의 관능 및 영양 특성 비교

남기호(Ki Ho Nam),김연계(Yeon-Kye Kim),박선영(Sun Young Park),이경돈(Kyung Don Lee),차장우(Jang Woo Cha),이경진(Gyeong Jin Lee),김진수(Jin-Soo Kim) 한국식품영양과학회 2018 한국식품영양과학회지 Vol.47 No.4

본 연구는 대표적인 내수면 어류인 철갑상어과 어류의 효율적 이용을 위하여 해수순치산 철갑상어의 식품성분 특성에 대하여 살펴보았고, 아울러 담수양식산 철갑상어의 식품성분 특성과도 비교 검토하였다. 해수순치산 철갑상어의 일반성분 함량은 수분이 78.0%, 조단백질이 19.1%, 조지방이 1.5%, 회분이 1.1%였고, 이는 담수양식산 철갑상어에 비하여 수분의 경우 낮았으나, 조단백질, 조지방, 회분의 경우 높았다. 해수순치산 및 담수양식산 철갑상어 근육의 에너지는 2종이 모두 100 ㎉/100 g 이하였다. 해수순치산 철갑상어의 헌터색조는 명도가 64.2, 적색도가 4.4, 황색도가 14.1이었고, 이는 담수양식산 철갑상어에 비하여 명도와 황색도의 경우 낮았고, 적색도의 경우 높았다. 해수순치산과 담수양식산 간에 경도는 유의적인 차이가 없었다(P>0.05). 해수순치산 철갑상어의 냄새 강도와 총 아미노산 함량은 각각 436.0 level 및 19.0 g/100 g이었고, 이는 담수양식산 철갑상어에 비하여 두 성분이 모두 높았다. 해수순치산 및 담수양식산 철갑상어 모두 주요 아미노산은 aspartic acid, glutamic acid, leucine 및 lysine이었다. 해수순치산 및 담수양식산 철갑상어 간에 무기질 함량과 지방산 조성은 유사하였다. 이상의 결과로 미루어 보아 해수순치산 및 담수양식산 철갑상어 간의 관능적 및 영양적 특성은 차이가 있는 것으로 나타났다. This study was conducted to compare the sensory and nutritional characteristics between sea-reared and freshwater sturgeons Acipenser oxyrinchus. The proximate composition of sea-reared sturgeon was 78.0% moisture, 19.1% crude protein, 1.5% crude lipid, and 1.1% ash. Thus, moisture content was lower while crude protein, crude lipid, and ash contents were higher than those of freshwater sturgeon. Regardless of culture methods, energy content of sturgeon muscle was 88.5∼95.9 ㎉/100 g. The Hunter color values of sea-reared sturgeon were 64.2 for lightness, 4.4 for redness, and 14.1 for yellowness. Thus, lightness and yellowness were lower while redness was higher than those of freshwater sturgeon. The hardness of sea-reared sturgeon was 4.1 ㎏/㎠, which was not significantly different (P<0.05) than that of freshwater sturgeon. The odor intensity of sea-reared sturgeon was 436.0 level, which was higher than that of freshwater sturgeon. The total amino acid content of sea-reared sturgeon was 19.0 g/100 g, which was higher than that of freshwater sturgeon. The major amino acids of the sturgeons were aspartic acid, glutamic acid, leucine, and lysine. The mineral contents and fatty acid composition of sea-reared sturgeon were similar to those of freshwater sturgeon. The results suggest that there were slight differences in sensory and nutritional characteristics between sea-reared and freshwater sturgeons.

악천후 시 낮은 도로조명을 이용한 도로 시인성 향상에 대한 연구

남기호,김충혁,최운식,Nam, Ki Ho,Kim, Chung Hyeok,Nam, Ki Ho 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.3

We investigate a fog-detection CCT control system using low deck lighting as a solution to the forward visibility of pole-type street lamps employed on existing roads. The lighting standards were met with a light source that has less compared with those of pole-type street lamps. The results show that the transmission rate was increased by changing the color temperature by automatically recognizing fog in bad weather and minimizing the phenomenon of lighting. In addition, it was allowed to create a safer and more comfortable driving environment for drivers owing to flicker or light pollution of existing pole-type street lamps. As a result, if lighting is used at a lower level than pole-type street lamps, the accident rate caused by securing the driver's forward visibility can be reduced sharply and existing problems can be resolved.

원자간력 현미경의 탐침외팔보의 정량적 특성평가를 위한 계측 시스템 개발

남기호(Ki-Ho Nam),권현규(Hyun-Kyu Kweon),홍성욱(Sung-Wook Hong) 한국기계가공학회 2005 한국기계가공학회 춘추계학술대회 논문집 Vol.2005 No.-